Research in the News: International team reconstructs the ancestor of placental mammals

By Bill Hathaway

February 7, 2013

The common ancestor of more than 5,000 contemporary placental mammals such as rats, whales, and humans was a small, insect-eating animal that appeared after the dinosaurs went extinct 65 million years ago, an international team of researchers report in the Feb. 8 issue of the journal Science.

Our evolutionary ancestor appeared about 36 million years more recently than molecular data had predicted, according to the analysis of more than 4,500 anatomical features analyzed by the team of scientists under the National Science Foundation’s Assembling the Tree of Life program.

“It would not have been possible to reconstruct the ancestral placental mammal or assess the relationships of extinct mammals without the large anatomical database we compiled in MorphoBank,” said Eric Sargis, professor of anthropology at Yale University, curator of mammalogy and vertebrate paleontology at the Peabody Museum of Natural History, and one of more than 20 scientists to collaborate on the project.